Fluid-pressure apparatus.



C. L. WALKER.

FL'UID PRESSURE APPARATUS.` APPLICATION FILED ,'AAY lo. 1912.

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C. L. WALKER.

FLUID PRESSURE APPARATUS. f

T|oN FILED MAY|o.1912.

Patented July 4, 1916.

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C. L. WALKER.

FLUED PRESSURE APPARATUS. .fPPLlcATeoN FILED MAY l0. |912.

CHARLES LESLIE WALKER, OF- LONDON, ENGLAND.

FLUID-PRESSURE APPARATUS.

Specification ofvLetters Patent.

Patented July 4, 1916.

Appiication mea may 1o, 1912. serial No. 696,394.

To all whom t may concern Be it known that I, CHARLES LEsLiE WALKER, a subject of the King of. Great Britain and Ireland, residing at 38a Boundary road, London, N. W., England, have invented certain new and useful Improvements in. Fluid-Pressure Apparatus, of which the following is a specification.

The invention deals with that class of mechanism in which cylinders are arranged in a circular manner side by side anda main object of the invention is to obtain 1n such mechanism, a theoretically equal output oreffective volume for each and every one of such cylinders throughout every variation of Huid-flow ratio. v

For the purposes of this specification the expression medial plane is to be understood as signifying that plane in a swash plate, disk, inclined member or allied partl whlch continually lies at right angles to the axis of such member and cuts both such axis and the axis of the apparatus in one and the same point.

The following description with the drawings represents an example of the manner of carrying out the invention.

Figure 1 is a vertical longitudinal section. Fig. 2 is a section on A Fig. 1 viewed in the direction of the dotted arrow. Fig. 3 is a section on the medial plane 12. Fig. 4 is a transverse medial section. Fig. 5 is a plan of the apparatus. Fig. 1 shows slightly more than one half of a variable iow liquid pressure apparatus which has two similar swash-plates shown dotted in Fig. 5, each controlling a set of pistons acting opposedly within one set of cylinders. The swash-plates have mechanism whereby they move synchronously with the barrel as hereinafter described.

The barrel 2 carrying cylinders 4, two swash plates or rings such as 7 with pistons and connecting rods, the driving shaft 1 with sleeves such as 10 and gearwheels such as 20, all revolve about their several axes; two inclined parts such as 9 secured to frames such as 27 with sun gear wheels such as 24, are all stationaryexcept during adjustment of flow-ratio. The casing 26 and the body 3 are permanently stationary. The left-hand half of the apparatus is exactly similar to the part shown, except that the partsgare reversed and that the left end of the shaft is adapted to receive the drive. The driving shaft 1 is secured to the cylin der barrel 2 which revolves within the valve The sleeve 10 has a spherical enlargement 10a Fig. 3 in which are formed tracks 14, la preferablyv parallel to each other. The ring 7 has two internal cylindrical projectlons 11 having a common axis which lies 1n the medial plane 12 and cuts the axes 13 and 8. The projections 11 have rollers 11a mounted on them which are engaged by the tracks l or' 14 and are adapted to transmit the torque from the sleeve 10 to the ring 7.

To the driving shaft 1 is rmly secured the member 16 having an arm 17 with pin 18 on which is mounted the eccentric 19 and integrally with it the toothed wheel 20 (Fig.

1). )ver the eccentric 19 is revolubly tted the rmg or roller 21. A fork 22 projects from the sleeve 10 the' inner surfaces of wh1ch are in planes each equidistant from, and parallel to, a plane in which the axis 13 lies. The surfaces form tracks which engage the ring or roller 21.

Projecting from the member 16 is a sec .ond arm 23 on which is mounted a pinion (not shown) which engages with the toothed sun 24. The said pimon also engages with the toothed wheel 20 which has half as many teeth as the toothed sun 24. The part25 is a counterweight. y The throw of the eccentric 19 is of such proportion that its action (in engagement with the fork 22) on the sleeve 10 causes the latter to oscillate with an angular amplitude equal to the versed sine of the angle which the axis 8 of the inclined member or ring 7 makes with the axis 13 of the apparatus, the oscillation of the sleeve 10 being relative to its coaxial element, namely, the

` shaft 1 with its adherent parts. The oscillating member 10, acting with the mechanism above described, anchors the inclined member 7 and so influences its motion as to cause it to rotate throughout each revolution at a constant speed, and thus its movement becomes synchronous with that of the shaft 1 and the parts fixed thereto. Consequently,

each piston (the parts being correctly cordinated) moves in true harmonic motion and with a stroke mathematically equal to that of all its neighbors. A constant flow of oil (if oil be the liquid used) is therefore obtained.

Within the casing 26 the frame 27 is revolubly fitted. The frame 27 (shown in two parts), has secured to it the inclined box 9 and the toothed ring 24. The frame 27 has circumferentially cut teeth 28 adapted to engage with the worm 29. A longitudinal shaft 37 see Fig. 5 engages with the worm 29 and simultaneously engages with the correspondingly placed worm on the left-hand portion of the apparatus, but in such a manner that if the worm 29 is revolved, so as to cause the frame 27 to turn in one direction any given angular distance, the corresponding frame on the left side will turn an equal distance, but in the contrary direction. The thrust balls 30 move only while speed is varied. The ring 7 has a circular hollow projection 31 the outer surface of which isspherical and adapted to fit a spherically concave surface of the Washer 32 which serves to maintain the ring 7 in its normal position when the apparatus is at rest or disengaged.

The barrel 2 is made to fit accurately within the body and valve chest 3, the formation of which is clearly shown in Fig. el, o-ne side of the valve together with the cylinders opening thereto being under eduction while the other side is under induction according to direction of flow.

' The recesses 33 (the axial positions of which are indicated in Fig. l by dotted lines) havetheir circumferential extent and positions shown dotted in Fig. 4. The (dotted) perforations 34: sufliciently indicate the manner in whichl the eduction and induction regions 35 have their pressures transmitted respectively to opposed pairs of recesses for the purpose ofbalancing the side pressures acting on the cylinder barrel 2. The supply and return connections are made at the openings 36.

b It will now be understood that if the longitudinal outer shaft 37, Fig. 5 (which turns the worm 29 and the corresponding worm 29 on the left) be actuated, the apparatus, used as a pump revolving at a constant speed, will give a varied flow. Thus, beginning with maximum direct How, the rate of flow may be gradually brought to zero flow, thereafter reversed, and gradually increased till the maximum reversed rate of iiow is reached z--In a first case, let the adjustment be such that, in one of the cylinders, both pistons are at the same instant at their inner dead centers, at which instant also the valve which controls the induction and eduction is at the point of momentary closure to the said one cylinder. It will be found that the medial planes are at -that each induction stroke the point of maximum angle with each other. Now, in a second case, let one of the frames (which maintain the medial planes ata given angle with the apparatus) be rotated about the `axis of the apparatus so that the medial plane is moved (in relation to the valvemember) in a clockwise manner through an angle of 90O and, at the same time, let the opposite frame be correspondingly moved (in relation to the valve-member) in an anti-clockwise manner through. an equal angle (of 90). It will be found now that the two medial planes are parallel as in the position shown dotted in Fig. 5. ln a third case let the" respective rotations be increased by 90O making now in each case 180. It will be found that the medial planes are again at their maximum angle with each other, but it will-also be found as become an eduction stroke and vice versa. In the second case the apparatus will be in the disengaged position.

It should be noted that vin any given position of adjustment between zero and maximum flow the volumetric effect of the two plungers which reciprocate in simple harmonic motion as described and comet-upon a single body of fluid is identical with the effect produced 'by the action of a single plunger which also moves in simple harmonic motion.

The present invention is derived from data observed in the examination by the inventor of the nature of the movements in space of a point which lies in the medial plane (above defined) of an acutely inclined bevel wheel which is in motion. The peculiar facts stated below are capable of mathematical demonstration. Let two equal bevel wheels be in mesh having their axis at any acute angle. To remove obscuring complications, instead of revolving about their axis in the more usual manner let one (having a horizontal axis) be fixed and let the other (having the linclined axis) execute a movement of precession, or, in other Words, let its axis describe cones, at a uniform speed. It is clear that the inclined wheel does not thus rotate. Any point which lies in the medial plane of the inclined wheel, and in fixed relationship thereto, will be found to describe a curve in space which is the resultant of two simple movements during the period of one precessional movement of the wheel, namely, an axially reciprocating movement in simple harmonic motion in relation to the fixed wheel combined with a twice repeated movement in a circle about a stationary horizontal axis. The said curve may be correctly marked `on the surface of a soA sphere or alternatively on that of a cylinder:

taking half the diameter of the said sphere as radius the diameter of the said cylinder will equal the versed sine of the angle of inclination of the axes of the inclined Wheel. If the angle of inclination be considerable the appearance of the curve, if viewed on the sphere, roughly resembles a figure 8 or/the outline of a sand-glass. If the said cylinder be superimposed within the said sphere, so that their two surfaces touch at a point, the line of intersection of the two mathematical bodies equals the said curve.

Let Fig. l now be examined in the light of the above remarks, and, for clearness, let the shaft 1 and the associated parts 2, 1G, etc., be regarded as stationary while the casing 26 and other parts 27, 9, 24 ctc. are rotated; it will be found that the inclined member 7 moves in a manner identical with the bevel wheel above described and every point in the medial plane 12 will describe a curve as above described. For example, if the axis of the eccentric 19 be drawn through the medial plane 12 the point of intersection thus found describes (in each revolution of the casing 26, 27) two circles around the (now fixed) axis of the wheel 20, marked with a dot-and-dash line in Fig. 1. Again, every point in the plane 12 which is the center of a ball-and-socket joint will circle (if the parts be correctly cordinated) twice in a revolution about lines which are the respective axes of the cylinders (as 4) thus each connecting rod (as 6) maintains a constant angle in relation to its cylinder axis. It Will be understood as a corollary of the above that the pistons must move in simple harmonic motion.

The irregularities and vibrations which are associated with universal joints, as hitherto usually constructed, are well known, but their magnitude at a given angle may be readily calculated in View of the above observations.

I claim:

1. A machine of the inclined-disk-Z-crank type in vwhich the inclined member is anchored through-the medium of a member .which is oscillated about an axis coincident 'clined member through the medium of the said roller, an element co-axial with the said oscillating member carr \,'ing a cylinder and supporting an eccentric which is in engagement with the said oscillating member a piston in the said cylinder actuated by the said inclined member and means whereby the said eccentric makes two rotations in the period of a double stroke of the said piston.

3. In an apparatus of the known order which comprises a distributing valve, two inclined members of constant inclination, a concentric element and two reciprocating agents cooperative on a single body of fluid and adapted respectively to co-act with the `said inclined members. Jfor the purpose of varying the effective-stroke, means of rotational contrariwise adjustment respectively of the two medial planes of the said inclined members relatively to the said valve about the axis of the said concentric element subsantially as described.

CHARLES LESLIE WALKER. 

